Converters
First Claim
1. A converter including D.C. input supply terminals, a load circuit including a high frequency transformer having primary and secondary windings, and an output rectifier, an oscillatory circuit including at least one capacitor and a parallel inductor connected in parallel with the primary winding of the transformer, and switching means including at least one solid state switching device, means for synchronizing the switching device to the oscillation of the oscillatory circuit for allowing the circuit to oscillate freely for part of a cycle to transfer energy from the inductor to the capacitor to charge the latter to a certain condition in which the voltage across the parallel inductor is substantial and that across the switching device is negligible and only then for connecting the parallel inductor across the D.C. input terminals whereupon the parallel inductor receives and stores energy from the said supply, and means connected in series in the load circuit for restricting load current to a low value during a part of the cycle in which the capacitor receives energy from the parallel inductor and until the capacitor is charged to the said condition and the switching means has connected the load circuit across the supply.
1 Assignment
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Accused Products
Abstract
A high frequency converter of push-pull form comprises a center tapped D.C. input supply 16, 17, 18, two solid state switching devices (20, 21) connected in series across the D.C. input terminals, a load circuit including a supersonic frequency transformer 30 and an output rectifier 35, and an oscillatory circuit including at least one capacitor 40 and a parallel inductor 34 connected in parallel with the primary winding 37 of the transformer between the center tapping 19 of the supply and the junction 25 of the switching devices. The switching devices are synchronized to the oscillation of the oscillatory circuit to allow the circuit to oscillate freely for part of a cycle to transfer energy from the inductor 34 to the capacitor 40 to charge the latter to a certain condition in which the voltage across the parallel inductor is substantial and that across the switching device is negligible and only then connect the parallel inductor across the D.C. input terminals whereupon the parallel inductor receives and stores energy from the said supply. Means such as a saturable reactor 33 are connected in series in the load circuit to restrict load current to a low value during a part of the cycle in which the capacitor receives energy from the parallel inductor and until the capacitor is charged to the said condition and the switching means has connected the load circuit across the supply.
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Citations
15 Claims
- 1. A converter including D.C. input supply terminals, a load circuit including a high frequency transformer having primary and secondary windings, and an output rectifier, an oscillatory circuit including at least one capacitor and a parallel inductor connected in parallel with the primary winding of the transformer, and switching means including at least one solid state switching device, means for synchronizing the switching device to the oscillation of the oscillatory circuit for allowing the circuit to oscillate freely for part of a cycle to transfer energy from the inductor to the capacitor to charge the latter to a certain condition in which the voltage across the parallel inductor is substantial and that across the switching device is negligible and only then for connecting the parallel inductor across the D.C. input terminals whereupon the parallel inductor receives and stores energy from the said supply, and means connected in series in the load circuit for restricting load current to a low value during a part of the cycle in which the capacitor receives energy from the parallel inductor and until the capacitor is charged to the said condition and the switching means has connected the load circuit across the supply.
- 12. A converter including D.C. input supply terminals an inductor unit including at least one inductor and two branches connected in parallel, each branch comprising a rectifier, the rectifiers being poled to conduct in opposite directions, a switching circuit including at least one solid-state switching device for causing current to pass alternately in opposite directions from the D.C. input terminals through the inductor, and means for preventing current flowing in a, or the, inductor during a period when the direction of current flow in the inductor is changing.
Specification